Electronically-controlled MMW beam-steering antennas the operation of which is based on the interaction of millimeter waves with solid-state plasmas in a planar semiconductor waveguide was disclosed in our paper entitled Monolithic Electronically-Controlled Millimeter-Wave Beam-Steering Antenna. The paper was delivered at the Topical Meeting on Silicon Monolithic Integrated Circuits in R.F. Systems, Sep. 17-18 1998, Ann Arbor, Mich., sponsored by the IEEE Microwave Theory and Techniques Society, NASA Lewis Research Center, Jet Propulsion Laboratory and Army Reserve Office.
The paper describes the need for a beam-steering antenna for a variety of applications such as automobile intelligent control and all-weather aircraft landing and notes that one of the most expensive components of systems suitable for such applications is the beam-steering antenna which performs sensor functions. The existing phased-array technology for electronic beam-steering does not meet the required compactness and cost efficiency criteria. The paper discloses a solid state antenna based on a reconfigurable plasma grating formed in a planar waveguide which performs beam-steering functions at MMW frequencies employing carrier injection to excite the required patterns.
The antenna disclosed in that paper comprises a silicon planar waveguide with an array of two-hundred PIN cells. All the cells have a common bottom ground electrode (N+type) and separate upper electrodes (P+type), the latter controllably connectable to a current source. The activated cells (pixels) are organized to create a periodic pattern of activated pixels which provides a plasma grating which operates as an amplitude deffraction grating for millimeter waves. A dielectric rod waveguide, set at a tunnel distance from the silicon substrate, is used as an antenna feeder.